Radial Artery Puncture

Arterial Puncture Sites

• The radial artery is located in the wrist on the radial side (thumb side), close to the surface of the skin.
• It is the site most commonly used for taking a patient's pulse.
• The radial artery has a collateral circulation, meaning that if circulation is interrupted, the ulnar artery will continue to supply the hand.
• There are no veins or nerves immediately adjacent to the radial artery, making it a safer site for arterial sampling.
• The radial artery is small, but can be punctured easily with careful observation, palpation, and practice.

Brachial Artery

• The brachial artery is located at the elbow in the antecubital fossa, on the medial side of the fossa near the insertion of the biceps muscle at the radial tuberosity.
• The brachial artery is larger and easier to palpate than the radial artery.
• However, it is close to both a large vein and a nerve, making it more susceptible to inadvertent venous sampling and nerve damage.
• The brachial artery does not have the advantage of collateral circulation, and inadvertent injury can result in the loss of the limb.

Femoral Artery

• The femoral artery is accessible for arterial sampling in the groin, and can be palpated laterally from the pubis bone.
• The femoral artery is very large.

Blood Gas Sampling Errors

• The reliability of blood gas analysis is very technique-dependent.
• Factors that contribute to sampling errors include:
  • Bubbles in the sample, which can diffuse oxygen and affect the PaO2 measurement.
  • Introduction of air into the sample, which can alter the blood gas results.
  • Inadequate mixing of heparin, which can cause clotting before sampling.

Supplies Needed for Arterial Puncture

• The supplies needed for arterial puncture are usually contained in an ABG kit.
• Separate supplies that may be needed include:
  • Pre-heparinized disposable sampling syringe
  • Needles (20 to 25 gauge, in various lengths)
  • Rubber stopper or rubber syringe cap
  • Adhesive strip or Elastoplast tape
  • Iodine and alcohol prep pads
  • Lidocaine anesthetic 2% solution (if ordered)
  • Disposable latex gloves
  • Eye protection (goggles or face shield)
  • Ice slush

Patient-Related Considerations

• A physician's order is required before performing arterial puncture or any other procedure.
• Check the patient's chart for a physician's order for anticoagulant therapy or oxygen therapy before arterial sampling.
• Coordinate therapy 2 hours before meals and tube feedings.
• Introduce yourself to the patient and explain the procedure.
• Assess the patient before therapy, including pulse rate, respiratory rate, Spo2, blood pressure, level of dyspnea, and level of consciousness.
• Auscultate the lung field before the procedure to identify the areas that need to be drained.
• Place the patient in the appropriate positions for drainage depending on the affected lobes/segments.
• Use pillows and foam wedges to help maintain the proper positions and ensure patient comfort.
• Monitor the patient before, during, and after the procedure, including subjective responses, breathing pattern, and sputum production.